Products, such as meat products and the like, are required to be held under a predetermined pressure, during processing in a variety of ways such as curing, smoking, cooking and the like. Such products may be processed in batches, or on some form of moving conveyor, depending upon the type of processing and the equipment available. In either case, however, it is essential that such products be packed into predetermined shapes and maintained under pressure during such processing. Since such processing may cause some shrinkage or swelling of the product, it is desirable that the product shall be subjected to pressure in such a way that if, for example, shrinkage takes place, the pressure will be maintained, and alternatively, if swelling takes place the pressure will not increase.
It is also essential that the products may be freely exposed to the atmosphere within the processing equipment. In some cases this may be necessary simply to remove vapourized moisture. In other cases it will be necessary in order that the heated atmosphere within the processing chamber, for example, shall be free to circulate completely around such products.
While different forms of equipment such as presses, and containers capable of applying pressure to products such as meat products, have been available for many years, they are not capable of fulfilling all of these various objectives.
In the case of typical processed or cooked meat products, such as hams and the like, the meat is removed from the bone, and separated into sections. The sections are then treated usually by injecting a solution such as brine, and then by massaging. The sections are then packed into casings made of a permeable material. Such stuffed casings are then placed in presses having upper and lower plates squeezing the stuffed casings so that the upper and under surfaces are flattened, and causing the sides to bulge. These presses are then passed through a processing chamber for cooking, smoking or the like.
This procedure involved considerable handling of product, and manipulation of small presses. In addition, the presses tended to obstruct free flow of atmosphere, smoke, etc. within the processing chamber, so that the product was subject to some degree of variation in treatment.
As meat processing lines become larger, and more complex, it is desirable that the presses shall be capable of handling larger volumes of product. At the same time, it is essential that the presses shall be of such a design that they may be easily loaded and unloaded with meat product, and also attached and detached from whatever conveyor system is used. It is also desirable to improve the free flow of atmosphere around the product. It is also essential that they should be capable of being cleaned and sterilized.